On HP 6500 printers, remove screen and try heating the connection elemants with hair dryer or something similar. Nothing to hot. The led bars should restore. Here's a link on how to remove HP 6500. Do same for 6500A model, but screen is a bit different, so check out the other video for HP 6500A and 6500A plus printers: HP 6500:

Try soaking printhead in the cleaning solution and it will resolve the issue. Check out the video on how to repmve printhead below. Put it in about half inch of solution which is 50% water, 40% window clening solution like windex, and some ammonia or rubbing alcohol.

Hi Check the following --Check the paper in the ADF (automatic document feeder)--Make sure the ADF pick assembly is in good working condition--Remove the document feeder and open the ADF cover.--While lifting the blue-green lever, carefully rotate the pick assembly toward the open ADF cover until it stops.--Make sure the bottom roller is held firmly in place by the two-catch, which is located to the left and the right of the roller.--Clean the rollers and separator pad

1. Plug it directly into the wall, rather than into a UPS2.
Verify that the unit is switched on. Disconnect the USB/Ethernet cable
from the All-in-One and also disconnect power cable from All-in-One and
also from wall outlet.3. Wait 30 seconds.4. Plug in the power cable to All-in-One and also to wall outlet.5. Check for the functionality.

I still had the error message, so they said to reset the printer to factory default settings:1. Unplug the power cable from printer when the printer is powered on and wait for 20 seconds.2. Then, press and hold # and 6 while plugging in the power cord.Continue holding until it displays Semi Full Reset message in the front panel of the All-in-One.

If those two steps do not resolve the problem then its is hardware related and can't be solved here.

I had the same problem; it happened with the first copy I tried to make directly from the printer's console - but only with the Black ink function - with the same original on the flatbed glass I then tried the Color function and it worked fine. But when I tried the Black copy function, the strong vertical lines appeared again - about 7, evenly spaced across the page and running the entire length of the page.

Nothing about cleaning any part made sense: the printer was brand new, out of the box, the color ink function worked fine to copy; so did making scan copies. It was only the black ink mode in the copy function with the original on the flatbed glass that produced the vertical lines.

What cleared it up was shutting it down, removing and re-inserting the power cord the other way, i.e., turning it around (which might have nothing to do with the outcome) and Voila! - no vertical lines with the black ink copy function - Go figure...

By this time, I may be an expert on this particular problem(that's a joke because anybody having this problem KNOWS that nobody has a solution, even, and especially HP). Sometimes you put so much time into something that it becomes personal(or stupid). But I did resolve this problem and I have done it 3 times(not by choice) so I feel this will work.

First and foremost, for anybody considering HP. Don't. Their hardware seems OK, but the software and support is awful. Don't even waste your time calling them.

Second, this is a painful process. Some that know better about registry updates may have a better solution, but I did it the hard way. So plan on spending a few hours to get through it.

Third, I don't know if this is important or not but buy a registry cleaner program. I used Registry Mechanic from PC tools. I am certainly not touting that product and I found some issues with it, but it's just what I used.
Fourth, this process works. But I'm going to be somewhat vague because I'm so tired of working on this issue that I don't want to take the time to provide exact detail. However, anybody that knows anything about Windows will understand this.

Here is the magical process(I have a HP 7680, but I think it will be the same for all models)
a) Uninstall the #?!!!$! HP software using the Uninstall from Control Panel.
b) Download the latest HP software for your printer from their site.
c) Run the Level 2, Level 3 and Level 4 Uninstall programs in the CCC folder of the software you just downloaded from HP(or, on the HP CD if you cannot download the latest version).
d) Scan your hard drive and delete any and all HP folders, including the "Hewlett Packard" folders. PLEASE NOTE: You probably will not be able to delete some folders because files are in use. You must delete these folders. Either reboot in safe mode to delete them, or shut off all services in msconfig(reboot required).
e) Delete the Twain32 folder in Windows folder
f) Empty the Recycle bin(probably not important, but I was taking no chance)
g) This would now be a good time to run your registry cleaner. This program should remove all registry entries that point to files that don't exist anymore. Registry Mechanic did not do this completely for whatever reason, but this should make the next step
h) backup your registry. The way I did this was "Start", "Run" and type msconfig. Click "Launch System Restore" and "Create a Restore Point". Do this, but be warned that there were a few times I tried to restore to one of these and the Windows process was unsuccesful. Didn't investigate why, but it happened, and more than once.
i) now the time consuming part. You are going to delete at least many hundreds of entries so get comfortable. Open the registry edito(regedit) and start scanning for these values. When you find them, delete the entire key, not just the key value(i.e. delete the folder on the left side of the regedit window). Sometimes you will get access denied. Just right click on the key and click "Permissions". Change the "Everyone" group to have full permission, then delete the key. This doesn't happen often - maybe 10 times? Also, please note that sometimes you will see that where the value was found, it has nothing to do with HP and so I left them alone. I would estimate 99% of what I found, I deleted. Believe me, you'll get good at this and your eyes will quickly identify the fact it's from an HP installation.
During this scan process, you will find reach a point where on the left side of regedit, there are dozens of folders that start with HP, all lined up nicely. Delete ALL of them.
1) Scan for and delete any folder(key) that contains "\hp". This is the hard one. Hundreds of them. (why didn't these get deleted by my registry cleaner program???)
2) Scan for and delete any key that contains "AIO"
3) Scan for and delete any key that contains "hp " (that is hp followed by a space. The search function allows this
4) Scan for and delete any key that contains "digital imaging"
5) Scan for and delete any key that contains "hewl"
j) almost there, and don't mess this part up. Make sure your printer is NOT connected. Reboot.
k) Reinstall using latest version. During installation, choose that you don't want HP software to check for updates and also, check the "custom" installation. When you reach the screen that lets you pick which programs to install, uncheck ALL of them that you can. You only want to install what is required. The rest is JUNK. When you reach the point where it wants to find the printer, do NOT hook the printer up. The software will assume you will hook it up later. Finish the installation and reboot.
l) run the install again. This time the menu will say "Add a device". Go ahead and click on that and hook up your printer(use USB). I did discover on one of my trips through this maze that it found the printer and installed it nicely, BUT, when I started HP Solution Center, it did not display the device. Then I ran Setup again, tried to install it as a network printer(cabled-not wireless). This failed but then, there it was the next time I opened Solution Center!! The process of trying to install network printer fixed something so don't give up once you get this far.
m) Good luck with this. I feel for all the people out there that just can't afford to go buy another printer. Again, I wouldn't touch HP with a mile long stick. The only reason I wouldn't give up is I was PISSED. I actually did this for somebody else, but I work for this person, so felt obligated to solve it. And I have HP printers at home, but, after researching this issue on the Internet and seeing what all of you have written, I will never buy HP again.